초록 ▼

The present invention relates to a method and apparatus for selective measurement of liquid and solid particles deposited on plate surfaces. The method is based on the transmission of radiation, which originates from total reflection from the interface between liquid droplets at the surface of the p

The present invention relates to a method and apparatus for selective measurement of liquid and solid particles deposited on plate surfaces. The method is based on the transmission of radiation, which originates from total reflection from the interface between liquid droplets at the surface of the plate and surrounding gas, e.g., air. This radiation is transferred inside the plate as radiation undergoing total internal reflection between the surfaces of the plate. Such measuring radiation reaches a detector protected from background radiation, whereby intensity increase can be measured and used for the control, e.g., windshield wipers and washer equipment.

대표청구항 ▼

[ I claim:] [1.] A method of detecting liquid and/or solid dirt on the surface of a transparent plate (1), in which method radiation emitted from a source (10, 11) of electromagnetic radiation and is received by at least one detector means (14) sensitive to said electromagnetic radiation, whereby th

[ I claim:] [1.] A method of detecting liquid and/or solid dirt on the surface of a transparent plate (1), in which method radiation emitted from a source (10, 11) of electromagnetic radiation and is received by at least one detector means (14) sensitive to said electromagnetic radiation, whereby the presence of liquid and/or dirt on the surface (2, 3) of said transparent plate (1) is detected in the form of an intensity change of the radiation received by said detector means (14), comprising(a) placing said source (10, 11) of radiation relative to the surface (2) of said plate (1) so that the radiation emitted by the source is incident via a gas-phase medium on the measured area of the surface of the plate (1), whereby the radiation is transmitted through the plate (1) to air without reflection when the plate is dry and/or clean, but a fraction of the radiation(i) undergoes refraction from liquid droplets deposited on the plate on the same side (2) as said source of radiation, or(ii) undergoes total reflection from liquid droplets (4) deposited on the surface (3) of the plate on the opposite side from said source of radiation, or(iii) is scattered by droplets of radiation-transparent medium containing solid particles deposited on the surface of the plate, as to make said fraction(s) of the radiation enter the inside of the plate (1),(b) transferring said fraction(s) of radiation due to presence of liquid and/or solid particles, in the inside of the plate (1) by total internal reflection to the detector means (14), and(c) detecting said fraction of radiation as an increase in the intensity of the radiation.